Every year in February (usually 3rd or 4th), the Japanese observe the “Bean Throwing Ceremony” or “Mamemaki”. As this time of the year also coincides with the division of seasons and the beginning of spring or “Setsubun”, most Japanese households (particularly, families with small children) carry out a “spiritual cleaning," to drive off evil and bring in fortune! Quite different from spring cleaning in the west, right?
Roasted, edible, soybeans are given to children, who throw it at a man dressed up as a demon (usually the father or male head of the household), while chanting:
"Out with the devil = Oni was soto”
"In with fortune = Fuku was uchi”
So a typical scenario would be excited children, running around the house, room to room, throwing beans and, literally driving the masked Mr. Devil out of the house." Once the devil is out, innumerous beans are scattered all over, which are then picked up, and each person eats the same number of beans as their age, to bring good luck.
Now you might wonder, since when had the bean become mightier than exorcism, in driving out the devil?
Well, it so happens that, for the Japanese, the bean provides the most protein, and is the basis of good health and energy.
Traditionally, this aspect associates the bean with toughness and unbreakable, strong willpower. Therefore, they are the best choice for keeping the devil and his bad luck out of Japanese homes and as a bonus, bring in health and happiness!
Well, the “sushi roll” is supposed to “Roll in happiness” and if you can eat the whole, uncut sushi in complete silence, your good human relations will not be cut off, rather get better! Surely, that must make you happy.
Although most modern Japanese people do not believe in the actual outcome of the ceremony, they are sporty enough to continue the tradition, which I think makes them who they are.